JP4165265B2 - Throttle opening control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throttle opening control device for an internal combustion engine that controls a throttle valve, which is arranged in an intake passage of the internal combustion engine and regulates an intake air amount into a combustion chamber, via an actuator such as a motor.
[0002]
[Prior art]
Generally, when deposits such as lubricating oil components adhere to the vicinity of the throttle valve in the intake passage of an internal combustion engine, the effective sectional area of the intake passage decreases and the intake air amount also decreases. . Therefore, in an internal combustion engine in which the basic fuel injection amount is calculated based on the throttle valve opening and the engine speed, when an amount of fuel corresponding to the throttle opening is injected with the deposit attached in this way, The air-fuel ratio becomes richer than the stoichiometric air-fuel ratio, or the engine speed cannot be set to a desired speed.
[0003]
In order to prevent the air-fuel ratio from deviating from the stoichiometric air-fuel ratio or deviating from the desired rotational speed due to such deposit adhesion, the deposit adhesion amount, in other words, actually in the combustion chamber The amount of air taken in is learned, and the learned value is reflected in the opening of the throttle valve. In this way, by reflecting the learning value of the deposit amount on the opening of the throttle valve, the air-fuel ratio of the internal combustion engine is maintained at the stoichiometric air-fuel ratio even when deposits are deposited, and the engine speed is set to a predetermined speed. Can be controlled.
[0004]
As such throttle opening control, there is a method disclosed in Patent Document 1. In this method, as shown in FIG. 7, the throttle valve flow rate characteristic C1 in a state where no deposit is attached in the vicinity of the throttle valve is translated by the throttle opening DLRN learned at a predetermined air amount Q11. A flow rate characteristic C2 indicated by a broken line is obtained. A flow rate characteristic C3 indicated by a chain line indicates a characteristic of an actual air amount after the deposit is attached. According to this method, in the vicinity of the throttle opening TA11 at which the learned air quantity Q11 is obtained, the throttle opening is controlled based on the flow characteristic C2, whereby the actual air quantity indicated by the flow characteristic C3 is set to the predetermined amount. Can be made substantially equal to the air amount Q11 of the engine, and the engine speed can be controlled to a predetermined speed.
[0005]
[Patent Document 1]
JP 11-270395 A
[0006]
[Problems to be solved by the invention]
However, the throttle opening control device described in Patent Document 1 has the following problems. That is, as shown in FIG. 7, in order to obtain a large air amount Q12 that is distant from the air amount Q11, a large throttle opening TA12 that is distant from the throttle opening TA11 is set based on the flow rate characteristic C2. Then, at this time, the actual air amount indicated by the flow rate characteristic C3 greatly deviates from the air amount Q12, and the engine rotation speed cannot be controlled to a predetermined rotation speed, so that the controllability of the throttle opening is lowered.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to control the throttle opening of an internal combustion engine that can suitably control the amount of air to the internal combustion engine to the required flow rate even after deposits are deposited. To provide an apparatus.
[0008]
[Means for Solving the Problems]
  In the following, means for achieving the above object and its effects are described.
  (1) The invention according to claim 1 is an internal combustion engine in which the engine rotational speed is brought close to a desired rotational speed by throttle control that manipulates the throttle opening while taking into account the deposit adhesion in the vicinity of the throttle valve provided in the intake passage. In the engine throttle opening control device, the flow rate characteristics that tend to change the intake flow rate with respect to the throttle opening, the inner diameter of the intake passage is the same, and the minimum opening that is the minimum value of the throttle opening is different from each other A plurality of flow rate characteristics in which the intake flow rate obtained by the minimum opening is substantially the same under the condition in which deposits do not adhere to the vicinity of the throttle valve are stored in advance.That is, a plurality of virtual flow rates each of a reference flow rate characteristic that is a flow rate characteristic having the same minimum opening as the actual minimum opening of the throttle valve and a flow rate characteristic obtained by removing the reference flow rate characteristic from the plurality of flow rate characteristics The characteristics are pre-stored,When no deposit adheres to the vicinity of the throttle valve,Of the aboveWhen the reference flow rate characteristic is selected and deposit adheres to the vicinity of the throttle valve, the actual flow rate characteristic under the condition that deposit adheres to the throttle valve among the plurality of flow rate characteristics. Close toRegarding the estimated flow rate characteristic that is different from the reference flow rate characteristic, the estimated flow rate characteristic is selected from the plurality of virtual flow rate characteristics based on the minimum opening degree of the reference flow rate characteristic and the minimum opening degree of the plurality of virtual flow rate characteristics. Selected,The gist of the throttle control is that the throttle opening is operated after the actual flow rate characteristic is the selected reference flow rate characteristic or the estimated flow rate characteristic.
  (2) The invention according to claim 2 is the throttle opening control device for an internal combustion engine according to claim 1, wherein the plurality of flow rate characteristics are provided under the condition that no deposit adheres to the vicinity of the throttle valve. The intake flow rate obtained by each minimum opening is set as the reference flow rate, and the throttle opening at which the reference flow rate can be obtained in the reference flow rate characteristic is corrected and opened under the condition that deposits adhere to the vicinity of the throttle valve. As a matter of fact, when deposits are deposited near the throttle valve, the gist is to select the estimated flow rate characteristic whose minimum opening is substantially the same as the corrected opening of the reference flow rate characteristic. .
  (3) The invention according to claim 3 is the throttle opening control device for an internal combustion engine according to claim 1 or 2, wherein the plurality of flow rate characteristics are stored in advance, and the plurality of flow rate characteristics are The calculation means for selecting the reference flow rate characteristic or the estimated flow rate characteristic and the control means for performing the throttle control based on the reference flow rate characteristic or the estimated flow rate characteristic.
[0009]
  (4) The invention according to claim 4 is an internal combustion engine in which the engine rotational speed is brought close to a desired rotational speed by throttle control that manipulates the throttle opening while taking into account the deposit adhesion in the vicinity of the throttle valve provided in the intake passage. In the engine throttle opening control device, the flow rate characteristics that tend to change the intake flow rate with respect to the throttle opening, the inner diameter of the intake passage is the same, and the minimum opening that is the minimum value of the throttle opening is different from each other The throttle opening is the same in a plurality of flow rate characteristics where the intake flow rate obtained by the minimum opening is substantially the same under the condition that no deposit adheres to the vicinity of the throttle valve, that is, the flow rate characteristic A1. The throttle opening is the same in the flow rate characteristic A2 and the intake flow rate C1 at the opening degree B1, which is the minimum opening degree of the characteristic A1. A plurality of flow rate characteristics that are the minimum opening of the quantity characteristic A2 and that are substantially the same as the intake flow rate C2 when the opening B2 is different from the opening B1 are stored in advance. As one of them, a reference flow rate characteristic, which is a flow rate characteristic actually obtained under the condition that no deposit adheres to the vicinity of the throttle valve, is stored.In addition, a plurality of flow characteristics different from the flow characteristics actually obtained under the condition that no deposit adheres to the vicinity of the throttle valve is obtained as the flow characteristics obtained by removing the reference flow characteristics from the plurality of flow characteristics. The virtual flow characteristics ofStorage means;It is determined whether or not there is a deviation between the actual value of the intake air flow calculated based on the engine operating state and the required value of the intake air flow calculated based on the throttle opening,When a determination result indicating that there is no deviation is obtained, when the reference flow rate characteristic is selected from a plurality of flow rate characteristics stored in the storage means, and a determination result indicating that a deviation occurs is obtainedThat is, when there is a deviation between the actual flow rate characteristic and the reference flow rate characteristic due to deposits adhering to the vicinity of the throttle valveThis is different from the above-mentioned reference flow rate characteristic, and the estimated flow rate characteristic that is close to the actual flow rate characteristic when deposits adhere to the vicinity of the throttle valve.Among the plurality of virtual flow characteristics, based on the minimum opening of the reference flow characteristics and the minimum openings of the plurality of virtual flow characteristics.And a control unit that performs the throttle control based on the flow rate characteristic, assuming that the actual flow rate characteristic is the flow rate characteristic selected by the calculation unit.
[0010]
  If deposits adhere to the intake passage of the internal combustion engine, the effective cross-sectional area of the intake passage decreases, and in order to obtain the required amount of air, the deposit is compared with the opening of the throttle valve when no deposit is attached. It is necessary to correct according to the amount.
At this time, according to each of the above-described configurations, the throttle valve having a fully closed set angle (minimum opening) at which the flow rate when fully closed becomes a substantially constant value differs depending on the amount of deposit after depositing. The opening degree of the throttle valve is controlled based on the flow rate characteristic. Here, the flow rate characteristic of the throttle valve to which the deposit is attached is substantially the same as the flow rate characteristic of the throttle valve having a different fully closed set angle (minimum opening) when the deposited deposit is converted into the throttle opening.
Therefore, the opening degree of the throttle valve with respect to the required air amount can be calculated, the required air amount can be obtained at any throttle opening degree, and the rotational speed of the internal combustion engine can be controlled to the required rotational speed. Become. In particular, the required air amount can be obtained even during the first idle control of the internal combustion engine or the idle up control during the cold state, and the engine rotation speed can be set to a desired rotation speed.
[0011]
  (5) The invention according to claim 5 is the throttle opening control device for an internal combustion engine according to claim 3 or 4, wherein the actual minimum value of the throttle valve is determined.OpeningIs determined by the angle of attachment of the throttle valve with respect to a vertical line with respect to the axis of the intake passage, and the reference flow rate characteristic is based on the angle of attachment of the minimum opening of the throttle valve in the flow rate characteristic. The gist is that it matches the minimum opening of the throttle valve.
[0012]
  (6) The invention according to claim 6 is the throttle opening control device for an internal combustion engine according to any one of claims 3 to 5, wherein the control means has a flow characteristic selected by the calculation means. In the throttle control based on the above, the required value of the intake air flow rate calculated based on the engine operating state is applied to the flow rate characteristic selected by the calculating means, so that it is necessary to make the actual intake air flow rate the same required value. The gist is to calculate a target value of the throttle opening and control the actual throttle opening based on the calculated target value.
As in the above configuration, multiple throttle valve flow characteristics with different fully closed set angles (minimum opening) are stored, and the throttle valve flow characteristics corresponding to the calculated fully closed set angle are selected and requested. Based on the flow rate and the selected flow rate characteristic of the throttle valve at the fully closed set angle (minimum opening), the opening control of the throttle valve can be suitably performed.
[0013]
  (7) The invention according to claim 7 is the throttle opening control device for an internal combustion engine according to any one of claims 3 to 6, wherein the calculation means calculates the deposit amount in the vicinity of the throttle valve. Based on this estimated adhesion amountAmong the plurality of virtual flow characteristicsThe gist is to select the estimated flow rate characteristic.
[0014]
  (8) The invention according to claim 8 is the throttle opening control apparatus for an internal combustion engine according to any one of claims 3 to 7, wherein the calculation means is configured so that an actual throttle opening is an arbitrary opening. The required flow rate, which is the intake flow rate obtained by this arbitrary opening degree under the condition that no deposit adheres to the vicinity of the throttle valve, and the intake flow rate actually obtained by this arbitrary opening degree And the amount of deposit adhering to the vicinity of the throttle valve is estimated based on the difference between the required flow rate and the actual intake flow rate.
According to this configuration, the reduction in the air amount caused by the deposit is calculated based on the difference between the required flow rate obtained based on the throttle valve opening and the air amount or actual air amount obtained based on the engine speed. Therefore, the amount of deposited deposit can be detected based on the decrease in the air amount.
[0015]
  (9) The invention according to claim 9 is the throttle opening control device for an internal combustion engine according to any one of claims 3 to 8, wherein the calculation means includes:Based on one of the minimum openings of the plurality of virtual flow characteristicsThe effective passage area is assumed to be passage area S1, and the deposit adheres to the vicinity of the throttle valve.Based on the throttle opening that is increased by a certain amount from the minimum opening of the reference flow rate characteristic to compensate for the effective passage area reduced by deposit adhesionThe effective passage area is defined as passage area S2,Among the plurality of virtual flow characteristicsWhen selecting the estimated flow characteristic from the above, the gist is to select, as the estimated flow characteristic, a flow characteristic in which the passage area S1 is substantially the same as the passage area S2.
[0016]
  (10) The invention according to claim 10 is the throttle opening control apparatus for an internal combustion engine according to any one of claims 3 to 9, wherein the calculation means includes:Based on engine speed and engine loadCalculating a required opening that is a required value of the throttle opening, calculating a difference between the actual throttle opening and the required opening, and selecting the estimated flow rate characteristic based on the calculated difference; It is said.
  As in the above configuration, the throttle opening according to the engine rotational speed and the load condition required for the engine is calculated, and a fully closed set angle (based on the difference between the current throttle opening and the calculated throttle opening ( The minimum opening) can be calculated.
[0017]
  (11) According to an eleventh aspect of the present invention, in the throttle opening control device for an internal combustion engine according to the tenth aspect, the calculation means adds the calculated difference to the minimum opening of the reference flow rate characteristic. Calculate the minimum opening after correction, andVirtual flow characteristicsThe gist of selecting the estimated flow rate characteristic is that the minimum opening is substantially the same as the corrected minimum opening.
[0018]
  (12) According to a twelfth aspect of the present invention, in the throttle opening control device for an internal combustion engine according to any one of the third to ninth aspects, the calculation means is a throttle calculated based on an engine operating state. About the required value of opening,Required intake flow rate based on engine speed and accelerator depressionThe required flow rate is calculated, the difference between the actual intake flow rate and the required flow rate is calculated, and the estimated flow rate characteristic is selected based on the calculated difference.
[0019]
  (13) In the thirteenth aspect of the present invention, in the throttle opening control device for an internal combustion engine according to any one of the third to twelfth aspects, the reference flow rate characteristic is stored in the storage means. Of the flow characteristics, the smallest opening is the smallest, that is, the minimum opening X of the reference flow characteristics isThe plurality of virtual flow characteristicsThe gist is that it is smaller than any of the minimum opening degrees Y.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment of a throttle opening control device for an internal combustion engine according to the present invention will be described below with reference to FIGS.
[0021]
First, with reference to FIG. 1, the outline | summary of the throttle opening control apparatus of the internal combustion engine concerning the embodiment is demonstrated. FIG. 1 schematically shows the outline of the overall configuration of the throttle opening control device for an internal combustion engine according to the first embodiment of the present invention.
[0022]
As shown in FIG. 1, the internal combustion engine 10 using gasoline as fuel is provided with an intake passage 21 for supplying intake air into the combustion chamber 20, and the intake passage 21 is supplied into the combustion chamber 20. A throttle valve 22 is provided for adjusting the amount of intake air in accordance with the opening. An intake pressure sensor 26 that detects intake pressure is provided downstream of the throttle valve 22 in the intake passage 21, and the detection signal is taken into a control device (ECU) 50 that performs various controls of the internal combustion engine 10.
[0023]
On the other hand, the amount of depression of the accelerator pedal 30 that requests the output of the internal combustion engine 10 is detected by an accelerator sensor 31 provided in the vicinity of the accelerator pedal 30, and the detected amount is taken into the ECU 50. The ECU 50 basically controls the motor 23 which is an actuator for opening and closing the throttle valve 22 so as to correspond to the depression amount of the accelerator pedal 30 and the opening degree of the throttle valve 22. Yes. A throttle position sensor 24 for detecting the opening degree of the throttle valve 22 is provided in the vicinity of the throttle valve 22, and the detection signal is taken into the ECU 50.
[0024]
The intake air introduced through the intake passage 21 is mixed with fuel such as gasoline injected from the injector 25 to be supplied into the combustion chamber 20 as an air-fuel mixture. The rotational speed of the internal combustion engine 10 is detected by a rotational speed (Ne) sensor 40 and taken into the ECU 50.
[0025]
The ECU 50 is configured as a logical operation circuit including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a backup RAM, and the like.
[0026]
Here, the ROM is a memory in which various control programs and maps that are referred to when executing these various control programs are stored, and the CPU performs arithmetic processing based on the various control programs and maps stored in the ROM. Execute. The RAM is a memory that temporarily stores calculation results from the CPU, data input from each sensor, and the like. The backup RAM is a non-volatile memory that stores data to be stored when the internal combustion engine 10 is stopped. . The ECU 50 is configured as a logical operation circuit in which a ROM, a CPU, a RAM, a backup RAM, an external input circuit, an external output circuit, and the like are connected by a bus.
[0027]
The ECU 50 controls the operating state of the internal combustion engine 10, such as fuel injection amount control, fuel injection timing control, ignition timing control, and throttle opening control, based on the engine speed or signals from various sensors (not shown). To do.
[0028]
By the way, when deposits such as lubricating oil components adhere to the inner wall of the intake passage 21 and the effective sectional area of the intake passage 21 decreases, the ECU 50 learns the deposit amount. In the present embodiment, the deposit adhesion amount is learned by calculating a fully closed set angle at which the inner diameter of the intake passage 21 is the same and the flow rate when the throttle valve 22 is fully closed becomes a substantially constant value. The fully closed set angle is a mounting angle when the throttle valve 22 is fully closed when a vertical line with respect to the axis of the intake passage 21 is used as a reference.
[0029]
For example, FIG. 3A shows a case where a deposit 27 corresponding to 1 ° in terms of the opening degree of the throttle valve 22 adheres to the intake passage 21 in the throttle valve 22 having a fully closed set angle of 6 °. Show. In this case, the distance between the throttle valve 22 and the deposit 27 when the throttle valve 22 is opened by 1 ° (actual effective area) is L1. FIG. 3B shows a throttle valve 60 having a fully closed set angle of 7 °, and the distance between the throttle valve 60 and the intake passage 21 when the throttle valve 60 is fully closed (actually effective disconnection). Area) is L1. Therefore, as shown in FIG. 4, the flow rate characteristic with respect to the opening degree of the throttle valve 22 after the deposit 27 shown in FIG. 3A is equal to the flow rate with respect to the opening degree of the throttle valve 60 shown in FIG. The characteristics are almost the same. Therefore, learning of the deposit adhesion amount is performed by calculating a fully closed set angle in which the inner diameter of the intake passage 21 is the same.
[0030]
Then, the ECU 50 stores in the ROM the flow rate characteristic maps of a plurality of throttle valves having different fully closed set angles as shown in part of FIG. ing. The ECU 50 selects a flow characteristic map of the throttle valve corresponding to the calculated fully closed set angle, and based on the required flow rate and the flow characteristic of the throttle valve of the selected fully closed set angle, the target opening of the throttle valve Is calculated, and the opening degree of the throttle valve 22 is controlled based on the target opening degree.
[0031]
Next, with reference to FIG. 2, the deposit adhesion amount learning executed by the ECU 50 and the opening degree control process of the throttle valve 22 based on the learning result will be described. This process is repeatedly executed at a predetermined time interval, for example.
[0032]
Next, the throttle opening control process executed by the ECU 50 will be described in detail with reference to the flowchart of FIG. This routine is repeatedly executed at predetermined time intervals.
[0033]
First, in step 100, the actual air amount calculated from the engine rotational speed detected by the rotational speed sensor 40 or the intake pressure detected by the intake pressure sensor 26 is read, and the throttle opening detected by the throttle position sensor 24 is also read. The degree is read.
[0034]
In the next step 102, it is determined whether or not deposits are accumulated based on the read engine speed or actual air amount and the throttle opening. Here, if there is a difference between the required flow rate obtained based on the opening degree of the throttle valve 22 and the air amount or actual air amount obtained based on the engine rotational speed, deposits are accumulated in the intake passage 21. Judgment can be made.
[0035]
Next, in step 104, it is determined whether the internal combustion engine 10 is warm idle. This is because the learning accuracy can be improved by learning the deposit adhesion amount during warm idling in which the change in the opening of the throttle valve 22 is small and the air amount is stable. If it is determined that the engine is not warm idle (step 104: NO), the process waits until the engine is warm idle. If it is determined that the vehicle is warm idle (step 104: YES), the process proceeds to step 106.
[0036]
In step 106, the required throttle opening corresponding to the engine speed and the load condition is calculated. Here, the load condition is a request for driving a load such as an air conditioner. When there is a request for driving the load, it is necessary to idle up.
[0037]
In the next step 108, the fully closed set angle deviation amount is calculated by subtracting the necessary throttle opening calculated in step 106 from the current throttle opening. By adding the fully closed set angle deviation amount and the initial fully closed set angle of the throttle valve 22, the fully closed set angle is calculated as a learning value of the deposit adhesion amount.
[0038]
In step 110, the target throttle opening is determined by subtracting the initial fully closed set angle from the throttle opening calculated based on the required flow rate Q with reference to the flow characteristic map corresponding to the calculated fully closed set angle. Calculated. Based on this target throttle opening, the motor 23 is driven to control the opening of the throttle valve 22.
[0039]
As described above in detail, according to the throttle opening control device of the present embodiment, the following effects can be obtained.
In the present embodiment, a fully closed set angle at which the flow rate when fully closed is a substantially constant value is calculated according to the amount of deposit adhering to the vicinity of the throttle valve 22, and the throttle valve corresponding to the fully closed set angle is calculated. The opening degree of the throttle valve is controlled based on the flow characteristics and the required air amount. Therefore, the opening degree of the throttle valve 22 relative to the required air amount can be calculated regardless of whether deposits are attached to the vicinity of the throttle valve 22, and the required air amount can be obtained at any throttle opening degree. The rotational speed of 10 can be controlled to a required rotational speed. In particular, the required air amount can be obtained even when the feedback control of the fuel injection amount is not performed, such as at the time of the first idle control of the internal combustion engine 10 or at the time of cold-up idle control, or at the time of deceleration control. The rotation speed can be set to a desired rotation speed.
[0040]
In this embodiment, the deposit amount near the throttle valve 22 is detected based on the engine speed or the actual air amount and the opening of the throttle valve 22 at that time. Therefore, it is possible to calculate the decrease in the air amount caused by the deposit based on the difference between the required flow rate obtained based on the opening degree of the throttle valve 22 and the air amount or actual air amount obtained based on the engine speed. Therefore, it is possible to detect the adhesion amount of the deposited deposit based on the decrease in the air amount.
[0041]
In this embodiment, a plurality of throttle valve flow characteristics with different fully closed set angles are stored, the flow characteristic of the throttle valve corresponding to the calculated fully closed set angle is selected, and the required flow rate and the selected flow rate are selected. Further, the opening degree of the throttle valve 22 is controlled based on the flow rate characteristics of the throttle valve with the fully closed set angle. Therefore, the opening degree control of the throttle valve 22 can be suitably performed based on the required flow rate and the flow rate characteristics of the selected fully closed set angle throttle valve.
[0042]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 6 focusing on differences from the first embodiment. In the present embodiment, the configuration of the internal combustion engine 10 and its surroundings is the same as in FIG.
[0043]
In the present embodiment, the calculation process of the fully closed set angle, which is the deposit adhesion amount learning process, is different from the first embodiment.
That is, after determining whether or not deposits are accumulated in step 102, in step 112, the required flow rate Q corresponding to the engine speed and the engine operating conditions is calculated. Here, the driving condition is a travel request such as the amount of depression of the accelerator pedal 30.
[0044]
In the next step 114, the flow rate difference Q0 is calculated by subtracting the current flow rate Qn from the required flow rate Q.
Next, in step 116, a fully closed set angle corresponding to the flow rate difference Q0 calculated in step 114 is calculated.
[0045]
Then, the target throttle opening is calculated by subtracting the initial fully closed set angle from the throttle opening calculated based on the required flow Q with reference to the flow characteristic map corresponding to the calculated fully closed set angle. Based on this target throttle opening, the motor 23 is driven to control the opening of the throttle valve 22.
[0046]
As described above in detail, according to the throttle opening control device of the present embodiment, the following effects can be obtained.
In the present embodiment, the required flow rate according to the current throttle opening and the engine operating conditions is calculated, and the fully closed set angle can be calculated based on the difference between the calculated required flow rate and the actual air amount. it can.
[0047]
The embodiment can be appropriately changed as follows, for example.
In each of the above embodiments, the target opening of the throttle valve 22 is calculated based on the flow characteristic map of the throttle valve corresponding to the calculated fully closed set angle and the required flow, but the calculation of the throttle opening and the flow is performed. Based on the equation, the target throttle opening degree of the throttle valve 22 may be calculated using the fully closed set angle as a parameter.
[0048]
In each of the above embodiments, the actual air amount is calculated based on the intake pressure detected by the intake pressure sensor 26. However, the actual air amount detected by an air flow meter provided upstream of the throttle valve 22 is employed. You may make it do.
[0049]
In each of the above embodiments, the internal combustion engine 10 using gasoline as fuel is embodied. However, an internal combustion engine that ignites the fuel with a spark plug, for example, LPG (liquefied petroleum gas) or LNG (liquefied natural gas) is used as fuel. It may be embodied in an internal combustion engine.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an internal combustion engine to which a throttle opening control device of a first embodiment is applied.
FIG. 2 is a flowchart showing a throttle opening degree control process according to the first embodiment.
FIGS. 3A and 3B are explanatory views showing the difference in the fully closed set angle of the throttle valve, respectively.
FIG. 4 is an explanatory diagram showing a relationship between a fully closed set angle of a throttle valve and a flow rate characteristic.
FIG. 5 is a flow characteristic map of a plurality of throttle valves having different fully closed set angles.
FIG. 6 is a flowchart showing calculation processing of a fully closed set angle according to the second embodiment.
FIG. 7 is an explanatory diagram showing a relationship between throttle opening and flow rate characteristics in conventional throttle opening control.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 20 ... Combustion chamber, 21 ... Intake passage, 22, 60 ... Throttle valve, 23 ... Motor, 24 ... Throttle position sensor, 25 ... Injector, 26 ... Intake pressure sensor, 27 ... Deposit, 30 ... Accelerator pedal , 31 ... accelerator sensor, 40 ... rotational speed sensor, 50 ... control device (ECU) as calculation means and control means, Q ... required flow rate.

Claims (13)

In a throttle opening control device for an internal combustion engine that brings the engine rotational speed close to a desired rotational speed by throttle control that manipulates the throttle opening while taking into account the depositing manner in the vicinity of the throttle valve provided in the intake passage,
Regarding the flow characteristics, which is the tendency of the change in the intake flow rate with respect to the throttle opening, the inner diameter of the intake passage is the same, the minimum opening that is the minimum value of the throttle opening is different from each other, and deposit adheres to the vicinity of the throttle valve A plurality of flow rate characteristics in which the intake flow rate obtained by the minimum opening is substantially the same under the condition where no engine opening occurs are stored in advance , that is, the minimum opening is the same as the actual minimum opening of the throttle valve. A reference flow rate characteristic which is a flow rate characteristic having a degree and a plurality of virtual flow rate characteristics which are each a flow rate characteristic obtained by removing the reference flow rate characteristic from the plurality of flow rate characteristics,
When the deposit does not adhere to the vicinity of the throttle valve, the reference flow rate characteristic is selected from among the plurality of flow characteristics. When the deposit adheres to the vicinity of the throttle valve, the plurality of flow characteristics Of these, the reference flow rate is estimated flow characteristics that are close to the actual flow characteristics under conditions where deposits are deposited near the throttle valve and are different from the reference flow characteristics. Based on the minimum opening of the characteristic and the minimum opening of the plurality of virtual flow characteristics, the virtual flow characteristic is selected from the plurality of virtual flow characteristics, and in the throttle control, the actual flow characteristic is the selected reference flow characteristic or estimation A throttle opening control device for an internal combustion engine, wherein the throttle opening is operated after having flow characteristics. The throttle opening control device for an internal combustion engine according to claim 1,
Under the condition that no deposit adheres to the vicinity of the throttle valve, the intake flow rate obtained by the minimum opening degree of each of the plurality of flow rate characteristics is used as a reference flow rate, and deposit adheres to the vicinity of the throttle valve. Under the condition, the throttle opening at which the reference flow rate is obtained in the reference flow rate characteristic is set as a corrected opening, and when deposit adheres to the vicinity of the throttle valve, the minimum opening is corrected for the reference flow rate characteristic. A throttle opening control device for an internal combustion engine, wherein the estimated flow rate characteristic is selected to be substantially the same as the degree. The throttle opening control device for an internal combustion engine according to claim 1 or 2,
Storage means in which the plurality of flow characteristics are stored in advance, calculation means for selecting the reference flow characteristics or the estimated flow characteristics from the plurality of flow characteristics, and the reference flow characteristics or the estimated flow characteristics And a throttle opening control device for an internal combustion engine. In a throttle opening control device for an internal combustion engine that brings the engine rotational speed close to a desired rotational speed by throttle control that manipulates the throttle opening while taking into account the depositing manner in the vicinity of the throttle valve provided in the intake passage,
Regarding the flow characteristics, which is the tendency of the change in the intake flow rate with respect to the throttle opening, the inner diameter of the intake passage is the same, the minimum opening that is the minimum value of the throttle opening is different from each other, and deposit adheres to the vicinity of the throttle valve The throttle opening is the minimum opening of the same flow characteristic A1 in a plurality of flow characteristics where the intake air flow obtained by the minimum opening is substantially the same under the condition where no flow occurs. The intake air flow rate C1 when the air flow rate is at the degree B1 and the intake air flow rate C2 when the throttle opening degree is the minimum opening degree of the flow rate characteristic A2 and the opening degree B2 different from the opening degree B1 in the flow characteristic A2. A plurality of flow rate characteristics that are identical to each other are stored in advance, and as one of the plurality of flow rate characteristics, deposits do not adhere to the vicinity of the throttle valve. Conditions of the reference flow characteristic storage is actually obtained flow characteristics under, and as the flow rate characteristics except for the reference flow characteristic from said plurality of flow rate characteristics, does not occur Deposit attachment to neighboring throttle valve Storage means for storing a plurality of virtual flow characteristics that are different from the flow characteristics actually obtained under
The actual value of the intake air flow rate calculated on the basis of the engine operating condition, determines whether deviation occurs between the required value of the intake air flow issued calculated based on the throttle opening degree, have deviation occurs When a determination result indicating that there is no deviation is obtained, the reference flow rate characteristic is selected from a plurality of flow characteristic stored in the storage means, and when a determination result indicating that a deviation has occurred is obtained , that is, to the vicinity of the throttle valve. When there is a deviation between the actual flow rate characteristic and the reference flow rate characteristic due to the deposit of the deposit, the deposit is caused in the vicinity of the throttle valve, which is different from the reference flow rate characteristic. estimation flow characteristics is close to the actual flow characteristics in terms of there, the plurality of temporary based this to the minimum opening degree of the minimum opening and said plurality of virtual flow characteristics of the reference flow characteristic A calculating means for selecting from among flow properties,
A throttle opening control device for an internal combustion engine, comprising: a control unit that performs the throttle control based on the flow rate characteristic, assuming that the actual flow rate characteristic is the flow rate characteristic selected by the calculation unit. The throttle opening control device for an internal combustion engine according to claim 3 or 4,
The actual minimum opening of the throttle valve is determined by the angle at which the throttle valve is mounted with respect to a vertical line with respect to the axis of the intake passage.
The reference flow rate characteristic is such that the minimum opening of the throttle valve in the flow rate characteristic matches the minimum opening of the throttle valve based on the mounting angle. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 5,
In the throttle control based on the flow rate characteristic selected by the calculation unit, the control unit applies a required value of the intake flow rate calculated based on the engine operating state to the flow rate characteristic selected by the calculation unit, To calculate the target value of the throttle opening required to make the actual intake flow rate the same required value, and control the actual throttle opening based on the calculated target value. Throttle opening control device. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 6,
The calculation means estimates an adhesion amount of deposit near the throttle valve, and selects the estimated flow rate characteristic from the plurality of virtual flow rate characteristics based on the estimated adhesion amount. Throttle opening control device. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 7,
When the actual throttle opening is an arbitrary opening, the calculating means is a request that is an intake air flow rate obtained by the arbitrary opening under the condition that no deposit adheres to the vicinity of the throttle valve. It is characterized by calculating the flow rate and the intake flow rate actually obtained from this arbitrary opening, and estimating the amount of deposit adhering to the vicinity of the throttle valve based on the difference between the required flow rate and the actual intake flow rate. A throttle opening control device for an internal combustion engine. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 8,
The calculation means sets the effective passage area based on any one of the minimum opening degrees of the plurality of virtual flow characteristics as the passage area S1, and deposit adherence under the condition that deposit adheres to the vicinity of the throttle valve. The effective passage area based on the throttle opening that is increased by a certain amount from the minimum opening of the reference flow rate characteristic to compensate for the effective passage area that has been reduced by the above is set as a passage area S2, and the above-mentioned virtual flow characteristics are selected from the plurality of virtual flow characteristics. A throttle opening control device for an internal combustion engine, wherein when selecting an estimated flow characteristic, a flow characteristic in which the passage area S1 is substantially the same as the passage area S2 is selected as the estimated flow characteristic. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 9,
The calculation means calculates a required opening that is a required value of the throttle opening based on the engine speed and the engine load, calculates a difference between the actual throttle opening and the required opening, and calculates the calculated difference A throttle opening control device for an internal combustion engine, wherein the estimated flow rate characteristic is selected based on The throttle opening control device for an internal combustion engine according to claim 10,
The calculation means calculates the corrected minimum opening by adding the calculated difference to the minimum opening of the reference flow rate characteristic, and the minimum opening of the plurality of virtual flow characteristics is the corrected minimum opening. What is substantially the same is selected as the estimated flow rate characteristic. A throttle opening control device for an internal combustion engine, wherein: In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 9,
The calculation means calculates a required flow rate that is a required value of the intake flow rate based on the engine speed and the accelerator depression amount, calculates a difference between the actual intake flow rate and the required flow rate, and based on the calculated difference A throttle opening control device for an internal combustion engine, wherein the estimated flow rate characteristic is selected. In the throttle opening control device for an internal combustion engine according to any one of claims 3 to 12,
The reference flow rate characteristic has the smallest minimum opening among the plurality of flow characteristics stored in the storage means, that is, the minimum opening X of the reference flow characteristic is the minimum opening Y of the plurality of virtual flow characteristics. A throttle opening control device for an internal combustion engine, which is smaller than any of the above.

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